Communication system



C. A. BORGESON COMMUNICATION SYSTEM Filed May 27, 1939 3 Sheets-Sheet l Nov. 11,194.1.

Nov. 11, 1941.v

C. Al BoRGEsoN 2,262,543 COMMUNICATION SYSTEM V Filed May 27, 1939 3 Sheets-Sheet 2 l F/G. 3

/NVENTOR CABORGESON y3M, fg?! A TTOR/VEV COMMUNICATION SYSTEM Filed May 2'7, 19139- 3 Sheets-Sheet 3 5 TA T/o/v 'STAT/0N /N I/E TOR c. A. oRGEso/v Patented Nov. 11, 1941V UNITED STATE COMMUNICATION SYSTEM Carl Anders Borgeson,` Eastranga N. J., as-

signor to American Telephone and Telegraph Company, a corporation of New York Application May 27, weasel-m1 No. 276,169.

l 6 claims. `(ci `Thisinvention relates to communication systems and particularly to telegraph systems where -intelligence is transmitted from Vpoint `to. point 4by permutation` code.

`The object of the vinvention is to provide service `for a plurality of subscribers at one point to a corresponding plurality ofsubscribers at another point over acommon channel which appears to each subscriber as a direct, individual and permanently established connection to another particular subscriber. Y e

l In accordance with this invention, an autoe l matic time allotter is provided so that equal-intervals are in turn allotted to each pair of subscribers `who are at any `time `operating their communication system. Where only a singlepair `of `subscribers are operating their system, the

full time of the channel is allotted to them, but where more than one pair are transmitting messages, then the `various pairs use the single channel share and share alike.

Iam aware of an arrangement disclosed in Patent No. 2,171,542, granted to Cunningham et al." Sept. 5, 1939, wherein the time of a `common channel linking a pair of synchronouslyV operat-L ing distributors is divided `among connections which appear to the subscribers to be direct `individual and permanently established connections between corresponding local stationsat apposite ends of such channel. I am aware of the fact that such appearance in this disclosure is maintained by the transmission between each character code over suchtcommon channel of signals identifying that `apparent connection `which is next to have the use of such common1 channel. 1

I am further aware of the disclosurein Patent 1No.`2,224=,250, granted toBorgeson et al. Dec. 1-0, `1940, wherein start-stop distributors l are employed at each end of a common channel and 1L identification signals are transmitted foreach operation of such start-stopdistributors prior to the transmission of intelligence signals for each apparent connection with the time of inactive connections given over to active connections.

I am further aware of the disclosure in Patent No. 2,207,314, granted to Cunningham et al. on

' VJuly 9, 1940, whereina Lnovel start-stop distributor means at each end of the commonV channelv is employed comprising a highv speed distributor ,for transmitting identication signals and a low speed `distributor for transmitting intelligence vsignals together with a circuit arrangement whereby the time of inactive connections is given overto and divided equally `and automatically among active connections. e

My contribution to this art is an arrangement .employing start-stop distributing means at the opposite ends of a common channel wherein the high` speed and a low speed distributor are used only at the transmitting end, wherein a low speed distributor onlyis used at the receiving end and vwherein the circuits and apparatusV em. ployed to perform the necessary functions are `cut downto nothing more than a single relay `per local station at each end. In the present `case the high speed distributor at the transmitting end acts as a sequence allotter and the low speed distributor which may be termed a time allotter in cooperation ywith the individual relay per local station operates to transmit both .identification andr intelligence signals.

A feature of the invention is .what may be termed, a sequence allotter which continuously utests ther various transmitting subscribers lines ,and stops at each in turn when they `wish to transmit. When such asubscribers line is in the. transmitting condition, this sequence allotter stops its movement, connects the line to the time allotter and after a predetermined period and under control of thev time allotter moves forward to test the next Ytransmitting subscribers line.

'Ihere the operation is repeated. If, however, .the

.secondtransmitting subscribers line is not in a transmitting condition, the sequenceallotter, does not pause but goes on immediately to another and next inorder line.

`In accordance with another feature of `the in- `ve1:1tion,`tl1e time allotter may be adjusted to allow the transmission of aplurality of character codes during each operation thereof'or it may be yadjusted to'allow the transmission of only a single character code. The design and adjust- Vment of this apparatus depends on the character of the service to be" rendered, and it may be varied over wide limits without in any manner departing from the spirit ofthe invention.

In accordance with another feature of the invention, both the sequence allotter and the time allotter are start-stop devices, that is, they are both driven by constantly rotating shafts through clutch arrangements so that they may be latched in a stationary position and then started at appropriate times through latch releasing actions. The` sequence allotter will continuously rotate until latched in a `stationary position when a subscriber starts to. transmit. The time allotter released under the same conditions. ,l

Another feature of the invention is an individual latching magnet in the sequence allotter for each station which by its energization under control of such station indicates in the sequence allotter a present capacity in said station to transmit.

Another feature is a single relay per station at each end of the common channel for connecting the station through the start-stop distributor thereat to the common channel. At the transmitting end such single relay is directly under control of the sequence allotter. Through the sequence allotter, this relay is also under the control of the station and the time allotter. At the receiving end, such single relay is under control of its associated relay at the transmitting end. After energization it is held under control by the start-stop distribution thereat.

'I'he drawings comprise three sheets containing Figs. 2, 3 and 4, which, placed as indicated in Fig. l, form a-circuit diagram illustrating the invention.

- 11n Fig. 2 there are shown two stations, the

upper marked station A and the lower marked station B. At the extremeleft of Fig, 4 there direct, individual andpermanently established'l connection between each other. Likewise, stations Band D form a pair. In the drawings, as shown, only the transmitting apparatus is shown at station A and only receiving apparatus is indicated Y at ystation C. yFor purposes of clarity, only oneway transmission is shown, but it will be understood that transmission in the other direction through similar apparatus and circuits may be carried on.

Station A comprises essentially a tape perforator I and a transmitting distributor designated by its'arm 2, and a motor 3 operated from a source of current 4 through a circuit'including a` switch 5. The slip clutch 6,'drives the shaft 1 ,w

through suitable gearing. Cam 8 on this shaft is' arranged to be engaged by a latch 9 through which position shown, the brush, on arm 2 makes con' nection froml positive battery to the line I3, this being a marking stop signal.

Branching off from the line I3 is a relay I4 for operating a monitoring printer I5. A switch I3, known as the tape switch, is closed when suiiicient tape has been punched t0 cause the apparatus at the station A to operate.

Station B is a duplicate of station A and operates in the same way,

In Fig. S'there is a relay I1 individual to station A and the relay I8 individual to station B. When relay I1 operates it connects the transmission line I3 from station A through the front contact and middle left armature to the intelligence segment I9 of the time allotter. When relay I8 is operated it connects the transmission line from station B to this same segment. When relay I1 is operated it connects the latch magnet of station A through the outer left armature to segment 20 of the time allotter and when relay I8 is operated it connects a similar point from station B to this segment. The tape switch I6 at station A controls latch magnet 2| of the sequence allotter and the tape switch of station B, in a like manner, controls the latch magnet 22 of the sequence allotter.

'I'he main part of Fig. 3 shows a constant speed motor 23 driven from a source of current 24 in a circuit including a switch 25. Through gears 26 and 21 the motor 23 drives the shaft 28 at a constant speed. 29 indicates a slip clutch through which the arm 38 of the sequence allotter is coupled to the shaft 28. The arm 30 is under control of latches operated by the latch magnets 2| and 22 and will rotate continuously at high speed when both of these latch magnets are deenergized. The speed at which this arm travels is preferably as high as possible, having due regard for the inertia of the various parts.

The shaft 28 also drives the shaft 3| through a series of gears 327 33, 34 and 35, though shaft 3| could as well be driven by a separate motor. As indicated by the proportions of these gears, the shaft 3| is driven at a slower speed than the shaft 28. In this case, a slip clutch 36 drives a distributor arm 31 when this arm is released by thelatch under control of latch magnet 38. During the greater proportion of the revolution of the arm 31, the brush 39 will be in Contact with the intelligence segment I9 and will connect this to the upper winding of relay 40 for transmission of intelligence over the line 4|. The length of time during which brush 39 engages intelligence segment I9 may be a period just suffi-cient to transmit the permutation code for one character or it may be a period long enough to transmit several permutation character codes. The exact design of this apparatus depends upon the commercial conditions,

In Fig. 4 there is shown a constant speed motor 42 driven from a source of power 43 through a circuit containing switch 44. This motor drives a shaft 45 through a pair of gears 46 and 41, A slip `clutch 48 serves to couple a distributor arm 49 to the shaft 45 when this distributor arm iS released by the latch magnet 50. The distributor arm 49 is constructed and arranged to travel at practically the same speed as the arm 31. For purposes of practical operation, the arm 49 should complete its revolution slightly ahead of the arm 31. The speed, however, must be accurate enough so that when the brush 39 contacts Ysegments 5|, the brush 52 will be in contact with segment 53. Likewise, when brush 39 is in contact with Vsegment 54, brush 52 must be in contact with segment 55. f

The operation is as follows: If station A is in a condition to transmit then the tapeswitch I6 4will be closed and latch magnet 2| will be energized. Therefore, arm 39 will be caused to stop in the position shown and, in this position, brush 59 will close a circuit from ground, ring 60, segment 6I to the winding of relay I1. Relay I1, becoming energized, connects the transmission line I3 to intelligence segment I9 as .hereinbefore noted and at the same time connects battery to segment 5I. Through its right-hand armature, relay |1`connects battery to the latch magnet 38 which withdraws the latch from arm 31 and allows this arm to start its travel. In the idle position as shown, brush 39 connects positive battery on segment 62 to the line segment 63, whereby a marking condition is normally held on the transmission line 4I. As soon, however, as magnet 38 becomes operated and withdraws the latch from arm 31,

to relay 40.

.faenas-43 Now as brush 31 passes over segment 5|, battery is connected through the inner left armature of relay l1, segment |,line segment "63 This relay goes marking and appliesground to conductor 4| whichv is extended .from line segmentll :over brush52 `to segment 53 and thence to the Winding Vof relay 65'. Relay 65`operates and locks to ground on the back contact of relay 66 so thatfforthe main part ofthe `rotation of arm49gthe line 4| `is extended.` from line segmentllfthrough brush 52 to segment 61 and thence over the right-hand armature and :front contact of relay 55-to linerelayfG. IThis :relay responds to the markrandspace signals -transmitted over line' I3 by the tape transmitter latr station A` andlrelays the permutation `code Vsignals to station C in `a Well-known manner;r`

During the rotation ofarm 31 the ,brushl 156 establishes `a connection vfrom battery `over `ring `ISllto' `segment 20 `and thence overthe outer left-handwarmature and `front contact of "relay I1, to the latch magnet ||1 atstation A. It should be noted that as the arm 31 i nears the completion `of a rotation, that this circuit `Wi1l"be broken in time to stop the distributor arm 2 before the brush 39 `has leftsegment I9. This arrangement may be made so that from one to any desired number of characters may be transmitted from station A while arm 31 is making a single revolution.

After the brush 56 has passed oi segment 20 and neared the point Where the arm 31 will be stopped by the latch controlled by magnet 38, a connection Will be made over brush 56 and segment 51 to relay 10 resulting in the energization of this relay. This will open the circuit of n latch magnet 2|, the latch will be Withdrawn and arm 30 will be allowed to move forward. Under the assumption that station A only is transmitting, latch magnet 22 will be deenergized and therefore, the arm 30 will not be stopped by magnet 22 when it gets into a position diagonally opposite to that shown but Will come around again to the position shown. In the meanwhile, arm 31 has advanced and relay 10 has become deenergized and latch magnet 2| has again become energized. Y

About the time-that relay is energized, brush 52 passes over segment 5B and causes the energization of relay 66 which releases i relay 65. Therefore, during one revolution of arm 31 and determined amount of transmission has taken place by the station A in its connection to station C.

If station B alone were in a condition to trans-` mit then the same sequence of events would take place with the exception that, in this case,

a connection would be made oversegment 54.

correspondingly, one revolution of arm 49, a preustorpedlby a latch,` magnet under control of the nextlstation in a condition `to transmit.` M

It `l'vvillbe at'once apparent "that Whereas only .two Vtransmitting' stations and tWoreceiving stations.` are shown, itis within `the' spirit of the -invention'to provide `a plurality.` This `.may be `done Aby `placing a `plurality. of segments, Vsuch .as 6|', in the path of the .brush 59 of the sequence ,'allotte'r.` In` like manner, there willbe aV correspending4 plurality of segments,` such as 5| and 54;` `and a corresponding 4plurality yof segments,

,such as 53 and55,` With appropriate relays, ysuch as 65 and 1|, to effectively connect theline` to the appropriate receiving stations. "Therepwill Jofhcoursebe a plurality of latch magnet'ssuch as 2| and 22 and aplurality of individual'relays What is claimedis: i i .v 1 l. Ina telegraph system, Samain linepstart- Astop apparatus including a distributorrconnected tothe ends of said `main line,a plurality ofi exten- .sion lines connected to therstart-stop apparatus at each endof said main` linezand an `auxiliary distributor cooperating withV said start-stop dis- -tributonlastart magnet for said auxiliaryI dis- 'tributor individualito each of saidl extension lines `connected to said start-stop distributor and opers a'tive connections between said auxiliary distrib- `utor.` and'said plurality of extension lines.` i

In a"communication system,a plurality `of subscribers stations at one` localitylinked'to` a like plurality `of subscribersy stations at vanother `locality over` `seemingly direct, individual and permanently established connections, -a common channel for said connections between said localities, transmitting means at one locality comprising a -high speed sequence allotter for automatically determining the order in which each of said connections shall use said common channel and a slow speed stop-start distributor for identifying every allotted connection by means of a different signal individual to each connection, and rendering it effective for a predetermined length of time, and receiving means at the other of said localities comprising a slow speed startstop distributor cooperating with said transmitting slow speed stop-start distributor for selecting the receiving end of each allotted connection and rendering it effective for a substantially equal lengthof time.

3. In a communication system, a plurality of subscribers stations at one locality linked to a like plurality of subscribers stations at another locality over seemingly direct, individual and permanentlyestablished connections, a common channel for said connections between said 1ocalities, transmitting means at one locality comprising a sequence allotter for automatically determining the order in which said connections shall use said common channel and a stop-start distributor for identifying and rendering effective for a predetermined period an allotted connection, operating means responsive to a ready to transmit condition at said stations for eiectively associating such stations with said transmitting means comprising a single relay only per station, receiving means at the'other said locality comprising a start-stop distributor for selectingthe receiving end of an allotted connection and rendering it effective for an equal length of time and operating means responsive to said receiving distributor for eiectively associating said receiving stations with said distributor comprising a single relay only per station.

4. In a communication system, a plurality of subscribers stations at onelocality linked to a like plurality of subscribers stations at another locality over seemingly direct, individual and pertransmit, a start-stop distributor for signaling over said common channel the identity of each 4allotted connection and for rendering said allotted connection effective for a predetermined period and means individual to each station `under joint control of said sequence allotter and said distributor for connecting an allotted connection to said common channel.

5. In a communication system, a plurality of subscribers stations at one locality linked to a like plurality of subscribers stations at another locality over seemingly direct, individual and permanently established connections, a common channel for said connections between said localities, a sequence allotter for automatically determining the order in which said connections shall use said common channel, means individual to each station for establishing a condition in said sequence allotter indicating a present capacity to transmit, a start-stop distributor for signaling over said common channel the identity of each allotted connection when said allotted connection is rendered elective and for rendering said allotted connection eiective for a predetermined period, a single relay only individual to each station for connecting an allotted connection through said distributor to said common channel and means jointly controlled by said distributor and said stations for controlling said relays.

6. In a communication system, a plurality of subscribers stations at one locality linked to a like plurality of subscribers stations at another locality over seemingly direct, individual and permanently established connections, a common channel for said connections between said localities, a sequence allotter for automatically determining the order in which said connections shall use said common channel, means individual to each station for establishing a condition in said sequence allotter indicating a present capacity to transmit, a start-stop distributor for signaling over said common channel the identity of an allotted connection and for connecting said common channel in said allotted connection for a predetermined period, only a single relay individual to each station for connecting said station to said distributor at the transmitting end of said common channel, a start-stop distributor at the receiving end of said common channel cooperating With said first distributor and only a lsingle relay individual to each station thereat for connecting each said station to said second distributor.

CARL ANDERS BORGESON. 

